Dumb-waiter lock



July 3, 1923. I

S. J. HOFF DUMB WAITER LOCK Filed June 6, 1922 INVENTOR $.Jfioff ATTORNEY Patented July 3, 123.

DU'lVLB-WAITER LOCK.

Application filed June 6, 1922. Serial No. 565,339.

ticularly to those used for securing the doors of dumbwaiters in the closed position' The main object being the provision of a lock which will secure the slide doors in a closed position and free from rattling.

Another object is to provide a look as described which can only be released from the inside, eliminating the use of a key with its attendant troubles such as the loss of the latter. As is well-known a lost key when found by an unauthorized person who can thus gain entry into an apartment by use of said key and most generally ransacking the same.

The above and other objects will become apparent in the description below in which characters of reference refer to the likenamed parts in the drawing. 7

Referring briefly to the drawing, Figure 1 indicates a front elevational view of a door opening used principally on a so-called dumbwaiter shaft and generally built into present day apartment houses.

Figure 2 is a sectional side elevational View of the same taken on line 2-2 of Figure 1.

Figure 3 is an enlarged front elevational view of the lock in the unlocked position.

Figure 4 is a side elevational view of the same.

Describing the drawing more in detail, the numeral 10 indicates the sashing which has frames 11 secured thereto, the latter be ing let into or imbedded in the wall 12 of the dumbwaiter shaft. able lift 13 within the shaft has shelves for the carrying of merchandise and is suspended from a sheave wheel, located at the top of the shaft, by a rope 14:.

An upper panel 15 is securely mounted within the sash and being immovable, forms a rigid member therewith. A. lower door panel 16 of similar dimensions to the upper is secured in recesses in the sashing and is capable of being slid open and when in the last-named position will assume a location directly adjacent to the upper panel 15.

A. vertically m0v- A sector 17 having horizontal extensions 18 which seat upon the upper e lge .19 of the lower door 16 and are secured in place by suitable screws. Said sector has a semi-circular periphery upon which ratchet teeth 20 are formed.

i A locking lever 21 rotatable about the center of the sector on a stud 22 has a pawl 23 pivoted at as which engages teeth 20 and prevents the rotation of the locking lever 21 to the unlocked position. A lug 25 extends V upwardly from pawl 23 and is engageable with a loci: release plunger 26. Said plunger is slidable on the lever having a knurled head 27 under which a coil spring 28 is retained for returning the plunger to the normal extended position after the latter has been depressed.

The opposite end of the plunger has a a conical end 29 which forms a cam action on the pawl lug 25 when contacting the latter, releasing the pawl 23 from engagement with the sector teeth 20.

A locking stud 30 secured near the outer end of the handle 21 is adapted to engage the underside of the curved wedge plate 31. The latter issecured to the upper panel 15 so that a declining wedge, surface is formed about the centering stud 22.

A handle lmob 32 is provided at the end of the lever 21 by which the latter is easily and conveniently manipulated.

In use, when the lower panel 16 is secured in the closed position, as illustrated in Figure 1, in which the locking lever 21 is in substantially vertical position with the stud 30 engaging the wedge plate 31 securely locking the panel so that the same cannot be opened from the outside. Obviously further rotation of the locking lever in the direction of the declined end of plate 31 will give a wedge or jam fit to the-door panel of greater degree than its preceding POSltlOll,

thereby preventing any rattling of the door.

plate 31 after which the door panel 16 can be readily I claim: v A lock for a vertically slid-able door cOn1 prising a toothed sector mounted on said slide door, a locking lever pivoted centrally slid upward to the open position.

on said sector and having stud member projecting therefrom, a curved plate secured to a wall above said door and enge'geahle with said stud when in locked position, said curved plate secured so as to form a wedge cam surface for jamming the door in closed position, a pawl member pivoted on said lever and engageahle with the toothed sector,

21 lug integral with said pawl, a pawl release plunger slidably mounted in said lever having a knurled headvthereon, a conicalhead on said plunger engageable with the lug and adapted to release the pawl from the sector when depressed and a spring for returning the same to normal.

In witness whereof I, afiix my signature.

SIGURD JAHR HOFF. 

